Add day only option for calendar embedding

[smartin98]

@nbren12

This just allows for the use case where the data has only daily resolution and second_of_day embedding in the calendar embedding becomes redundant.

embeddings.py:
CalendarEmbeddingOnlyDay is the same as CalendarEmbedding except for returning only the day_of_year channels in the embedding. Still takes second_of_day argument for compatibility but this is not used.

networks.py:
Added flag in SongUNet to enable the OnlyDay embedding, defaults to False.

[nbren12]

line is too long. Is the linter passing?

[smartin98]

shortened and fixed the linter errors

[nbren12]

Needs test coverage:

1. add a test like this here

   cBottle/tests/unit/test_networks.py

   Line 181 in 4d299fa

   def test_CalendarEmbedding():

2. add pytest.mark.parametrize for the new option here:

   cBottle/tests/unit/test_networks.py

   Line 196 in 4d299fa

   def test_SongUnetCalendarEmbeddings():

[smartin98]

Needs test coverage:

1. add a test like this here https://github.com/NVlabs/cBottle/blob/4d299faf0fd83135422bfa29a3590655a502084a/tests/unit/test_networks.py#L181

2. add pytest.mark.parametrize for the new option here: https://github.com/NVlabs/cBottle/blob/4d299faf0fd83135422bfa29a3590655a502084a/tests/unit/test_networks.py#L196

added tests

[nbren12]

@smartin98 These tests are failing

tests/unit/test_networks.py::test_SongUnetCalendarEmbeddings[False] FAILED [ 89%]
tests/unit/test_networks.py::test_SongUnetCalendarEmbeddings[True] FAILED [ 90%]

[smartin98]

@nbren12 sorry for the delay on this, I fixed the test and rebased to main.